I bought the handle from the thrift store. It was actually a staircase spindle that I embedded into the entire head for rigidity. Although I did later end up cutting it off because I wanted a wrapped handle look that didn't work with the handle I had.

Between the last pic and this, I chamfered the corners to match the designs and glued strips of styrene along the inner edges. To give the head some more surface impact resistance, I sprayed plastidip all over it.
You can see in the lower right hand the starts of the center circles. However, these weren't used because the clay cracked and broke easily when drawn that thin.

Big gap in picture taking here. I had started using textured spray paint everywhere because it went on so thick that it hid every surface imperfection and gave a wonderful and uniform rocky texture.
For the center circles, I ended up going to walmart, buying some cheap bangles and gluing them in place. I read that woodfiller made a good cosplay putty, so I started using a lot of it for this part. I spread the woodfiller over the bangle, then used a notched piece of plastic to kind of scrape off the excess and give it a beveled shape. Unfortunately, the wood filler wasn't the best consistency for this and scraping in a circle shape is really hard.

Here's a mock up of the head and the handle 2.0. Unfortunately, I don't have any in progress shots of the handle because I had a friend help me out with it. It's 12 strips of faux leather crisscross wrapped around a 1-3/4" oak dowel.

Here's a mock up with the end knob on as well. The knob was just a drawer pull knob that I tried to match up somewhat with reference. I filled in the harsher edges and end of it with wood filler.
Because I had no access to a lathe, I put the knob in my power drill and made an improvised lathe. It worked out fairly well actually.